Marijuana concentrates are products that contain THC or THCA in concentrated amounts. In this article we will discuss these products starting from the most basic to the most pure.



Kief is the powder on the bottom left.

Cannabis flower has tiny trichomes on it that contain a significant amount of THCA. They are barely visible with the eye. When these trichomes dislodge from the flower and fall to the bottom of a container, they can be collected into a powder called kief. In some ways this is the most basic form of a marijuana concentrate. It can be squeezed and pressed into larger pieces or it can be sprinkled onto flower to make it stronger. Usually it is smoked along with flower.

Kief can be made at home by using a grinder with a screen on the bottom (see picture) to grind marijuana flower. Over time, the trichomes fall through the screen and collect until enough is accumulated that it can be added to flower.




Kief can be turned into a pliable putty called hashish (or “hash” for short) that is also used on flower to increase its potency for smoking. Traditionally, it was made in the Middle East and India by handling marijuana plants with bare hands until they are sticky from cannabis and then rubbing them together to collect the sticky substance and create a putty. Hashish is usually a brown to black substance and has been used more in Europe than in America. Now that cannabis has become legalized in American states, it is also produced here and sold in dispensaries but it is less popular than other concentrates, which are more pure. Hashish tends to contain biproducts and unnecessary contaminants when it is bought on the street. You can imagine the palm sweat that is contained in illegally imported hashish….



Butane Hash Oil (BHO)

Nature’s Way Medicine
Butane Hash Oil (BHO)

A more refined concentrate was discovered sometime at the end of the last century. This concentrated form of cannabis has become the precursor for all modern day concentrates. It was created by packing pipes with ground-up marijuana and passing butane gas through them. The gas would dissolve the THC and other fat-soluble molecules and pour out of the end of the pipe in a sticky liquid. After letting it dry you had an amber-colored sticky, hard material that was named Butane Hash Oil (BHO). The consistency would vary so it would be labeled based on its properties. Shatter is hard and literally shatters when pushed on. Wax appears waxy. There are many names to this type of concentrate but the overall product is now the basis for most concentrates in dispensaries. It can be used for vaporization or added to flower before smoking, like kief.


Rick Simpson Oil


Rick Simpson Oil (RSO)

Around the time that BHO was becoming popular, there was a man in Canada named Rick Simpson who discovered a different way of preparing cannabis oil. Instead of using butane, his method involved alcohol. Rick would grow marijuana and use the flower by mixing it with rubbing alcohol. After straining out the flower, the alcohol contained dissolved THCA. He would then cook the alcohol to boil and evaporate it. Not only did this leave behind a dark oil from the flower but it also activated the THCA into THC. The oil could be directly eaten and had physiological activity. It does not need to be cooked again or heated to activate it. This Rick Simpson Oil (RSO), as it is known, was given to cancer patients and apparently improved their cancer, sometimes curing it (this hasn’t been scientifically verified).

Rick Simpson Oil (RSO) is usually sold in syringes.

Rick saw such amazing results on cancer patients that he went public with his findings even though he was growing marijuana illegally. Eventually, he was exiled and had to leave his home country. Today he lives in Croatia and advocates for medical marijuana, writing books and speaking about cannabis publicly. His invention has been used all over the world and today RSO has become one of the most recommended cannabis products for patients with cancer. It is very potent and allows for high doses of THC to be swallowed. Sometimes Rick would have his patients eat as much as 2 grams of RSO as part of their treatment.



Rossin being pressed.

Probably the most natural way to create concentrate is by squeezing it out of the flower like a lemon with lemon juice. It requires some extra help though with heat, filter bags, and a high-pressure press. The result is a concentrate called rosin.

The earliest way this was done was with a hair straightner in a vise (like the kind on a work bench). If you place the marijuana flower in some parchment paper between the hair straightener and squeeze it while it is hot with the vise, the flower will ooze concentrate. This method is not recommended and will produce minimal concentrate and has risk of injury and failure.

Medical Marijuana Clinic
Rosin can have different consistencies and shades depending on the strain used.

Improved techniques were developed and now there are rosin presses available on the market that have heated clamps. To keep the flower out of the rosin, it is placed in a bag that retains the flower but allows the concentrate to pass through and out of the flower during pressing. In the picture above you can see rosin after a pressing and the left over bag of flower in the center. The yellow rosin is picked off the paper and stored so it can be vaporized later.

Rosin retains more flavor from the original strain of flower because it contains more terpenes that are in the flower. It isn’t processed the way other concentrates are and there is no need for adding a solvent (like butane or ethanol to extract the THC) that can be left behind in the product.

Rosin Press.



Marijuana can be distilled in a laboratory. Products using this technique are typically less viscous (more liquid) and sold in syringes. The distillation process separates the THC or THCA in cannabis and then later terpenes are added to it. The additives are sometimes called a sauce and are from cannabis or synthetically made. These distillates are labeled “full spectrum” if they contain a wide array of terpenes but generally adding terpenes has no medical benefit and just changes the flavor of the product. Distillates commonly use liquid CO2 to extract THCA from the cannabis. This is sometimes called CO2 oil.


Pure THC and THCA

THC Crystals
THC crystals. The yellow color is from additives like terpenes (sauce).

The best quality and purest cannabis product is pure THC or THCA. When purified completely (99.9%) it results in a crystalized form. Dispensaries will sometimes add sauce (see above) to this, which will provide them more profit by diluting the active ingredient. When sauce is added, the dispensaries will call the product crystals. When the pure THC or THCA is sold on its own, it is called diamonds. Diamonds are the most prized form of medical marijuana because it is 100% active ingredient and less can be used to achieve the desired effect. It is free of contaminants and additives that provide no medical value. However, this is the most potent form of cannabis and should only be used by experienced users.